CN111586765B

CN111586765B - Method and device for relay communication

Info

Publication number: CN111586765B
Application number: CN201910117716.2A
Authority: CN
Inventors: 罗海燕; 戴明增
Original assignee: Huawei Technologies Co Ltd
Current assignee: Huawei Technologies Co Ltd
Priority date: 2019-02-15
Filing date: 2019-02-15
Publication date: 2023-01-13
Anticipated expiration: 2039-02-15
Also published as: EP3913974A4; US20210377834A1; CN111586765A; WO2020164613A1; EP3913974A1

Abstract

The application provides a method and a device for relay communication. The first terminal device receives, from the second terminal device, indication information for instructing the second terminal device to stop providing the relay service between the first terminal device and the radio access network device. The first terminal equipment sends the notification information to the wireless access network equipment through the third terminal equipment to inform the wireless access network equipment that the first terminal equipment is accessed to the wireless access network equipment through the relay service of the third terminal equipment, so that the wireless access network equipment can communicate with the first terminal equipment through the third terminal equipment, the situation that the first terminal equipment suddenly finds that the second terminal equipment cannot relay, communication between the first terminal equipment and the wireless access network equipment is interrupted, and the communication efficiency is improved.

Description

Method and device for relay communication

Technical Field

The present application relates to the field of communications, and in particular, to a method and an apparatus for relaying communication.

Background

In the third generation partnership project (3 gpp) standard, cell handover of a first terminal device is mainly performed based on control of Radio Resource Control (RRC) messages of an access network device. Specifically, when moving, the first terminal device sends the signal quality of the target cell detected by the first terminal device to the radio access network device, and the radio access network device determines whether cell handover is required according to the signal quality of the target cell and other factors. When handover is required, an RRC message is sent to the first terminal device, where the RRC message may carry an identifier of a target cell to which the first terminal device is to be handed over.

In a scenario in which a first terminal device communicates with a radio access network device through other terminal devices as a relay device, the radio access network device may send an RRC message to the first terminal device through the other terminal devices along with movement of the first terminal device to indicate a target relay device to which handover is to be performed. It is assumed here that the second terminal device is a terminal device currently providing a relay service between the first terminal device and the radio access network device, and the third terminal device is a terminal device potentially providing a relay service between the first terminal device and the radio access network device. If the first terminal device suddenly moves from the coverage area of the second terminal device to the coverage area of the third terminal device, or the signal quality between the second terminal device and the radio access network device becomes poor or even a radio link fails, the first terminal device may not receive the RRC message sent by the radio access network device through the second terminal device, and the switching of the relay device may not be performed, so that the communication between the first terminal device and the radio access network device is interrupted or the communication efficiency is reduced.

Disclosure of Invention

The application provides a method and a device for relay communication, which can improve communication efficiency.

In a first aspect, a method for relaying communication is provided, where the method includes: the first terminal equipment receives indication information from the second terminal equipment, wherein the indication information is used for indicating that the relay service between the first terminal equipment and the wireless access network equipment is stopped to be provided; the first terminal device sends notification information to the radio access network device through a relay service of a third terminal device, wherein the notification information indicates that the first terminal device is connected to the radio access network device through the third terminal device.

The first terminal device receives indication information indicating that the second terminal device stops providing relay service for the first terminal device and the wireless access network device from the second terminal device, and sends notification information to the wireless access network device through the third terminal device to notify the wireless access network device that the first terminal device is connected to the wireless access network device through the relay service of the third terminal device, so that the wireless access network device can communicate with the first terminal device through the third terminal device, and therefore the situation that the first terminal device suddenly finds that the second terminal device cannot relay, communication interruption between the first terminal device and the wireless access network device is caused is avoided, and communication efficiency is improved.

In some possible implementations, the indication information indicates that a signal quality between the second terminal device and the radio access network device is less than or equal to a preset quality threshold.

The indication information may indirectly indicate, by using the signal quality between the second terminal device and the radio access network device being less than or equal to the preset quality threshold, that the second terminal device stops providing the relay service between the first terminal device and the radio access network device.

In some possible implementations, the indication information indicates that a radio link failure occurred between the second terminal device and the radio access network device.

The indication information may indirectly indicate, through a radio link failure occurring between the second terminal device and the radio access network device, that the second terminal device stops providing a relay service between the first terminal device and the radio access network device.

In some possible implementations, the indication information further indicates an identifier of the third terminal device, and the method further includes: and the first terminal equipment determines the third terminal equipment according to the identifier of the third terminal equipment.

The indication information can also indicate the identifier of the third terminal device, so that the first terminal device can determine the terminal device (namely, the third terminal device) which can currently perform relay service for the first terminal device and the wireless access network device, and further send the notification information to the wireless access network device through the third terminal device, so that the wireless access network device can communicate with the first terminal device through the third terminal device, thereby avoiding that the first terminal device suddenly finds that the second terminal device cannot perform relay, resulting in the communication interruption between the first terminal device and the wireless access network device, and improving the communication efficiency.

In some possible implementations, the notification information further indicates an identity of the first terminal device.

The notification information can also indicate the identifier of the first terminal device, so that the radio access network device can know that the relay device between the first terminal devices corresponding to the identifier switches according to the identifier, and thus, under the condition that the plurality of first terminal devices switch relays, the radio access network device can accurately know which first terminal device the notification information is sent, and when the first terminal device communicates, the switched relay device is adopted, so that the communication efficiency is improved.

In some possible implementations, the method further includes: and the first terminal equipment sends the identifier of the third terminal equipment to the second terminal equipment.

The first terminal device may further send the identifier of the third terminal device to the second terminal device when determining that the third terminal device is a device currently relaying the first terminal device and the radio access network device, which may help to forward data of the first terminal device through the third terminal device when the data of the first terminal device is not completely forwarded, thereby avoiding data loss of the first terminal device and improving signal quality.

In a second aspect, a method for relaying communication is provided, the method comprising: the second terminal equipment generates indication information, and the indication information is used for indicating that the relay service between the first terminal equipment and the wireless access network equipment is stopped to be provided; and the second terminal equipment sends the indication information to the first terminal equipment.

The second terminal device generates indication information indicating that the second terminal device stops providing relay service for the first terminal device and the wireless access network device, and sends the indication information to the third terminal device, so that the third terminal device sends notification information to the wireless access network device according to the indication information to notify the wireless access network device that the first terminal device accesses the wireless access network device through the third terminal device, and thus the wireless access network device can communicate with the first terminal device through the third terminal device, thereby avoiding that the first terminal device suddenly finds that the second terminal device cannot relay, resulting in communication interruption between the first terminal device and the wireless access network device, and improving communication efficiency.

In some possible implementations, the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than a preset threshold.

The indication information may indirectly indicate that the second terminal device stops providing the relay service for the first terminal device and the radio access network device by a radio link failure occurring between the second terminal device and the radio access network device.

In some possible implementations, the method further includes: the second terminal device sends the data to be sent of the first terminal device to a third terminal device, the third terminal device is a device which currently provides relay service for the first terminal device and the wireless access network device, and the second terminal device is a device which previously provides relay service for the first terminal device and the wireless access network device.

The second terminal device sends the data to be sent of the first terminal device to the third terminal device, so that the data to be sent of the first terminal device can be forwarded through the third terminal device under the condition that the data of the first terminal device is not forwarded completely, the data loss of the first terminal device is avoided, and the signal quality is improved.

In some possible implementations, the sending, by the second terminal device, the to-be-sent data of the first terminal device to the third terminal device includes: the second terminal device sends a first message, where the first message includes the data to be sent, and the first message also includes an identifier of the first terminal device, an identifier of a first channel, and transmission direction indication information, and the first channel is used for communication between the first terminal device and the radio access network device.

The second terminal device may carry the data of the first terminal device through the first message, and the first message may also carry the identifier of the first terminal device, the identifier of the first channel, and the transmission direction indication information, so that the third terminal device may know that the data carried in the first message is the data belonging to the first terminal device, and know that the channel identifier of the first channel corresponding to the data of the first terminal device, and whether the data of the first terminal device is the data needing uplink transmission or the data needing downlink transmission, so that the third terminal device may send the data of the first terminal device to the opposite communication terminal in a suitable channel, thereby further improving the communication efficiency.

In a third aspect, a method for relaying communication is provided, where the method is applied in a communication system including a first terminal device, a second terminal device, a third terminal device and a radio access network device, where the third terminal device is a device that currently provides a relay service for the first terminal device and the radio access network device, and the second terminal device is a device that provides a relay service for the first terminal device and the radio access network device before the third terminal device, and the method includes: the second terminal device receiving data belonging to the first terminal device; the second terminal device sends a first message to the third terminal device, where the first message includes data of the first terminal device and notification information, the notification information is used to indicate an identifier of the first terminal device, a DRB identifier for data radio bearer, and direction indication information, the DRB identifier is used to indicate a DRB between the first terminal device and the radio access network device, and the direction indication information is used to indicate a transmission direction of the data of the first terminal device.

There may be multiple bearers for performing communication between the first terminal device and the radio access network device, where the bearer may be a DRB, where the first message carries a bearer identifier corresponding to certain data (hereinafter, referred to as data of the first terminal device) of the first terminal device, an identifier of the first terminal device, and direction indication information, where the direction indication information may indicate whether the data of the first terminal device is uplink data or downlink data. In addition, the data and the notification information of the first terminal device may be carried in the same message (i.e., the first message), so that the third terminal device can know, when receiving the first message, which terminal device the data included in the first message is, and the DRB identifier corresponding to the data of the first terminal device, so that the third terminal device can accurately determine, according to the first message, to which receiving end the data of the first terminal device is sent (e.g., to which channel between the third terminal device and the radio access network device the uplink data is sent, and to which channel between the third terminal device and the radio access network device the downlink data is sent), and which channel is used (i.e., to which channel between the third terminal device and the radio access network device, or to which channel between the third terminal device and the first terminal device), thereby improving communication efficiency.

In some possible implementation manners, the notification information is carried in sidelink control information SCI, and a time domain resource occupied by the SCI is the same as a time domain resource of the data belonging to the first terminal device, or the time domain resource occupied by the SCI is before the time domain resource occupied by the data belonging to the first terminal device.

By carrying the notification information by SCI, resources specially used for transmitting the notification information do not need to be configured, thereby saving signaling overhead.

In some possible implementations, the notification information is carried in an adaptation layer of the first message.

In a fourth aspect, a communication apparatus is provided, which may be a stand-alone terminal device or a chip in the terminal device. The apparatus has the functionality to implement the first aspect and various possible implementations described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In one possible design, the apparatus includes: a receiving module and a transmitting module, the receiving module or the transmitting module may be at least one of a transceiver, a receiver, a transmitter, for example, or the receiving module or the transmitting module may include a radio frequency circuit or an antenna. The apparatus also includes a processing module, which may be a processor.

Optionally, the apparatus further comprises a storage module, which may be a memory, for example. When included, the memory module is used to store instructions. The processing module is connected to the storage module, and the processing module can execute the instructions stored in the storage module or other instructions from other sources, so as to cause the apparatus to perform the method of the first aspect or any one of the above aspects.

In another possible design, when the device is a chip, the chip includes: the chip comprises a receiving module and a sending module, and optionally, the chip further comprises a processing module, and the receiving module and the sending module may be, for example, an input/output interface, a pin, a circuit, or the like on the chip. The processing module may be, for example, a processor. The processing module may execute instructions to cause a chip within the terminal to perform the communication method of the first aspect and any possible implementation.

Alternatively, the processing module may execute instructions in a memory module, which may be an on-chip memory module, such as a register, a cache, and the like. The memory module may also be located within the communication device but outside the chip, such as a read-only memory (ROM) or other type of static storage device that may store static information and instructions, a Random Access Memory (RAM), etc.

The processor mentioned in any of the above may be a general-purpose Central Processing Unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), or one or more integrated circuits for controlling the execution of programs of the communication methods in the above aspects.

In a fifth aspect, a communication apparatus is provided, where the apparatus may be a terminal device or a chip in the terminal device. The apparatus has the functionality to implement the second aspect and various possible implementations described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In one possible design, the apparatus includes: the device comprises a processing module and a sending module, wherein the sending module can be at least one of a transceiver and a transmitter, and the sending module can comprise a radio frequency circuit or an antenna. The processing module may be a processor.

Optionally, the apparatus further comprises a storage module, which may be a memory, for example. When included, the memory module is used to store instructions. The processing module is connected with the storage module, and the processing module can execute the instructions stored in the storage module or the instructions from other sources, so as to enable the apparatus to execute the communication method of the second aspect and various possible implementation manners. In this design, the apparatus may be a radio access network device.

In another possible design, when the device is a chip, the chip includes: the processing module and the sending module, sending may be, for example, an output interface, pin, or circuit on the chip, etc. The processing module may be, for example, a processor. The processing module may execute instructions to cause a chip within the terminal to perform the communication method of the second aspect and any possible implementation.

Alternatively, the processing module may execute instructions in a memory module, which may be an on-chip memory module, such as a register, a cache, and the like. The memory module may also be located within the communication device but external to the chip, such as a read-only memory or other type of static storage device that may store static information and instructions, a random access memory, and so forth.

The processor referred to in any above may be a general purpose central processing unit, a microprocessor, an application specific integrated circuit, or one or more integrated circuits for controlling the execution of programs for the communication methods of the above aspects.

In a sixth aspect, a communication apparatus is provided, where the apparatus may be a terminal device or a chip in the terminal device. The apparatus has the functionality to implement the third aspect and various possible implementations described above. The function can be realized by hardware, and can also be realized by executing corresponding software by hardware. The hardware or software includes one or more modules corresponding to the functions described above.

In one possible design, the apparatus includes: a receiving module and a transmitting module, the receiving module or the transmitting module may be at least one of a transceiver, a receiver, a transmitter, for example, and the receiving module or the transmitting module may include a radio frequency circuit or an antenna. The apparatus also includes a processing module, which may be a processor.

Optionally, the apparatus further comprises a storage module, which may be a memory, for example. When included, the memory module is configured to store instructions. The processing module is connected to the storage module, and the processing module can execute the instructions stored in the storage module or instructions derived from other instructions, so as to enable the apparatus to execute the communication method of the third aspect and various possible implementations. In this design, the apparatus may be a terminal device.

In another possible design, when the device is a chip, the chip includes: a receiving module and a sending module, which may be, for example, input/output interfaces, pins or circuits on the chip, etc. The processing module may be, for example, a processor. The processing module may execute instructions to cause a chip within the terminal to perform the communication method of the third aspect and any possible implementation.

Alternatively, the processing module may execute instructions in a memory module, which may be an on-chip memory module, such as a register, a cache, and the like. The memory module may also be located within the communication device but outside the chip, such as a read-only memory or other type of static storage device that may store static information and instructions, a random access memory, and the like.

The processor referred to in any above may be a general purpose central processing unit, a microprocessor, an application specific integrated circuit, or one or more integrated circuits for controlling the execution of programs for the communication methods of the above aspects. In a fifth aspect, a computer storage medium is provided, in which program code is stored, the program code being used for instructing to execute instructions of the method in the first aspect or any possible implementation manner thereof.

In a seventh aspect, a computer storage medium is provided, in which program code is stored, the program code being used for instructing to execute the instructions of the method in the first aspect or any possible implementation manner thereof.

In an eighth aspect, a computer storage medium is provided, in which program code is stored, the program code being used for instructing to execute instructions of the method in the second aspect, the third aspect, or any possible implementation manner thereof.

In a ninth aspect, there is provided a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of any possible implementation of the first aspect described above.

A tenth aspect provides a computer program product comprising instructions which, when run on a computer, cause the computer to perform the method of the second aspect, the third aspect, or any possible implementation thereof.

In an eleventh aspect, there is provided a processor, coupled to a memory, for performing the method of the first aspect or any possible implementation thereof.

In a twelfth aspect, there is provided a processor, coupled to a memory, for performing the method of the second aspect, the third aspect, or any possible implementation manner thereof.

In a thirteenth aspect, there is provided a chip comprising a processor and a communication interface, the communication interface being used for communicating with an external device or an internal device, the processor being used for implementing the method of the first aspect or any possible implementation thereof.

Optionally, the chip may further include a memory having instructions stored therein, and the processor may be configured to execute the instructions stored in the memory or derived from other instructions. When executed, the instructions are for implementing a method of the first aspect described above or any possible implementation thereof.

Alternatively, the chip may be integrated on the terminal device.

In a fourteenth aspect, a chip is provided, where the chip includes a processor and a communication interface, where the communication interface is used to communicate with an external device or an internal device, and the processor is used to implement the method in the second aspect or the third aspect or any possible implementation manner thereof.

Optionally, the chip may further include a memory having instructions stored therein, and the processor may be configured to execute the instructions stored in the memory or derived from other instructions. When executed, the instructions are for implementing a method in the second or third aspect described above, or any possible implementation thereof.

Alternatively, the chip may be integrated on the terminal device.

Based on the above technical solution, the first terminal device receives, from the second terminal device, indication information indicating that the second terminal device stops providing relay service for the first terminal device and the radio access network device, and sends, according to the indication information, notification information to the radio access network device through the third terminal device to notify the radio access network device that the first terminal device accesses the radio access network device through the third terminal device, so that the radio access network device can communicate with the first terminal device through the third terminal device, thereby preventing the first terminal device from suddenly discovering that the second terminal device cannot perform relay, resulting in communication interruption between the first terminal device and the radio access network device, and improving communication efficiency.

Drawings

FIG. 1 is a schematic diagram of a communication system of the present application;

fig. 2 is a schematic diagram of a user plane protocol stack in the communication system of an embodiment of the present application;

fig. 3 is a schematic diagram of a control plane protocol stack in the communication system according to the embodiment of the present application;

FIG. 4 is a schematic flow chart diagram of a method of relaying communications in one embodiment of the present application;

FIG. 5 is a schematic diagram of a transmission channel of an embodiment of the present application;

fig. 6 is a schematic flow chart of a method of relaying communications of another embodiment of the present application;

fig. 7 is a schematic flow chart of a method of relaying communications of yet another embodiment of the present application;

FIG. 8 is a schematic block diagram of an apparatus for relaying communications according to an embodiment of the present application;

fig. 9 is a schematic configuration diagram of an apparatus for relaying communication according to an embodiment of the present application;

fig. 10 is a schematic block diagram of an apparatus for relaying communication according to another embodiment of the present application;

fig. 11 is a schematic configuration diagram of a device for relaying communication according to another embodiment of the present application;

fig. 12 is a schematic block diagram of an apparatus for relaying communication according to still another embodiment of the present application;

fig. 13 is a schematic configuration diagram of an apparatus for relaying communication according to still another embodiment of the present application;

fig. 14 is a schematic block diagram of an apparatus for relaying communication according to still another embodiment of the present application;

fig. 15 is a schematic block diagram of an apparatus for relaying communication according to still another embodiment of the present application;

fig. 16 is a schematic block diagram of an apparatus for relaying communication according to still another embodiment of the present application.

Detailed Description

The technical solution in the present application will be described below with reference to the accompanying drawings.

The technical scheme of the embodiment of the application can be applied to various communication systems, for example: global system for mobile communications (GSM) systems, code Division Multiple Access (CDMA) systems, wideband Code Division Multiple Access (WCDMA) systems, general Packet Radio Service (GPRS), long Term Evolution (LTE) systems, LTE Frequency Division Duplex (FDD) systems, LTE Time Division Duplex (TDD), universal Mobile Telecommunications System (UMTS), worldwide Interoperability for Microwave Access (WiMAX) communication systems, future fifth generation (5 g) systems, or New Radio (NR) systems, etc.

The first terminal device in the embodiments of the present application may refer to a user equipment, an access terminal device, a subscriber unit, a subscriber station, a mobile station, a remote terminal device, a mobile device, a user terminal device, a wireless communication device, a user agent, or a user equipment. The first terminal device may also be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), a handheld device with wireless communication function, a computing device or other processing device connected to a wireless modem, a vehicle-mounted device, a wearable device, a first terminal device in a future 5G network or a first terminal device in a future evolved Public Land Mobile Network (PLMN), and the like, which are not limited in this embodiment. In addition, in each embodiment of the present application, the method steps executed by the terminal device may be specifically implemented by at least one chip in the terminal device.

The radio access network device in this embodiment may be a device for communicating with a first terminal device, and the radio access network device may be a Base Transceiver Station (BTS) in a global system for mobile communications (GSM) system or a Code Division Multiple Access (CDMA) system, may also be a base station (NodeB, NB) in a Wideband Code Division Multiple Access (WCDMA) system, may also be an evolved base station (evolved, eNB, or eNodeB) in an LTE system, may also be a radio controller in a Cloud Radio Access Network (CRAN) scenario, or may be a relay station, an access point, a vehicle-mounted device, a wearable device, a radio access network in a future 5G network, or a radio access network in a PLMN network of a future evolution, and the like, and the present embodiment is not limited.

In an embodiment of the present application, the first terminal device or the radio access network device includes a hardware layer, an operating system layer running on top of the hardware layer, and an application layer running on top of the operating system layer. The hardware layer includes hardware such as a Central Processing Unit (CPU), a Memory Management Unit (MMU), and a memory (also referred to as a main memory). The operating system may be any one or more computer operating systems that implement business processing through processes (processes), such as a Linux operating system, a Unix operating system, an Android operating system, an iOS operating system, or a windows operating system. The application layer comprises applications such as a browser, an address list, word processing software, instant messaging software and the like. Furthermore, the embodiment of the present application does not particularly limit the specific structure of the execution subject of the method provided in the embodiment of the present application, as long as the program recorded with the code of the method provided in the embodiment of the present application can be executed to perform communication according to the method provided in the embodiment of the present application, for example, the execution subject of the method provided in the embodiment of the present application may be the first terminal device or the radio access network device, or a functional module capable of calling the program and executing the program in the first terminal device or the radio access network device.

In this case, the application program for executing the method for relay communication according to the embodiment of the present application and the application program for controlling the receiving end device to complete the action corresponding to the received data may be different application programs.

Fig. 1 is a schematic diagram of a communication system of the present application. In the wireless communication system 100, the relay device 103 may be configured to provide a relay service for the at least one first terminal device 105 and the radio access network device 101. The number of the relay devices 103 may be one, or may be multiple, that is, multiple relay devices simultaneously provide the relay service for the first terminal device and the radio access network device. The relay device is a terminal type node, and the relay device and the first terminal device communicate through a sidelink (also called a PC5 port).

It should be noted that the wireless communication system 100 shown in fig. 1 is only for more clearly illustrating the technical solution of the present application, and does not constitute a limitation to the present application, and as a person having ordinary skill in the art knows, the technical solution provided in the present application is also applicable to similar technical problems as the network architecture evolves and new service scenarios emerge.

Fig. 2 shows a schematic diagram of a user plane protocol stack in the communication system according to the embodiment of the present application. A terminal device as a relay device has only a Radio Link Control (RLC) layer/Medium Access Control (MAC) layer/Physical (PHY) layer protocol stack in a user plane facing a first terminal device, and has only an adaptation layer (adaptation)/RLC/MAC/PHY protocol stack in a user plane facing a radio access network device (e.g., eNB of LTE system or en-gbb, gbb of NR system). The following radio access network device takes an eNB in an LTE system as an example. The adaptation layer mainly includes information for identifying at least one of an identifier of the first terminal device at the PC5 port, a radio bearer (DRB) identifier of the first terminal device, or a Logical Channel Identifier (LCID) between the corresponding first terminal device and the relay device. In addition, in the communication system shown in fig. 2, a Packet Data Convergence Protocol (PDCP) layer of the first terminal device and a PDCP layer of the eNB are transparently transferred by the relay device, that is, an end-to-end PDCP layer is provided between the terminal device and the eNB, and the relay device does not analyze the PDCP layer. The first terminal device and the relay device in the embodiment of the application may communicate through an LTE/NR Uu air interface, or a PC5 interface, or a sidelink (sidelink) interface, communicate between the relay device and the eNB through the LTE/NR Uu air interface, and communicate with the core network through S1-U between the eNB and the CN and an S5 or S8 interface inside the CN. When the radio access network device is a gNB in the NR system, the terminal device communicates through an NG3 port between the gNB and the CN.

Fig. 3 shows a schematic diagram of a control plane protocol stack in the communication system according to the embodiment of the present application. The terminal device as the relay device has only the RLC/MAC/PHY protocol stack when facing the first terminal device, and has only the adaptation layer (adaptation)/RLC/MAC/PHY protocol stack when facing the radio access network device. In the communication system shown in fig. 3, the RRC layer and the PDCP layer of the first terminal device and the RRC layer and the PDCP layer of the radio access network device are transparent to the relay device, that is, the terminal device and the eNB have the end-to-end RRC layer and PDCP layer therebetween, and the relay device does not analyze the PDCP layer and the RRC layer. In addition, the control plane of the first terminal device further includes a non-access stratum (NAS) layer, and the NAS layer of the first terminal device and the NAS layer of the core network are transparently transferred through the relay device and the radio access network device. The first terminal device and the relay device may communicate through an LTE/NR Uu air interface, or a PC5 interface, or a sidelink (sidelink) interface. The relay equipment and the eNB communicate through an LTE/NR Uu air interface, and the terminal equipment communicates with the core network through an S1-MME between the eNB and the CN. When the radio access network device is a gNB in the NR system, the terminal device communicates through the NG2/NG3 port between the gNB and the CN.

Fig. 4 shows a schematic flow chart of a method of relaying communication according to an embodiment of the present application.

The first terminal device receives indication information from the second terminal device, the indication information indicating that the second terminal device stops providing the relay service between the first terminal device and the radio access network device 401. Accordingly, the second terminal device transmits the indication information to the first terminal device.

In particular, the second terminal device may be a device that currently provides a relay service between the first terminal device and the radio access network device.

It should be understood that the first terminal device in the embodiment of the present application may be generally referred to as a remote user equipment (remote user equipment), which is not limited in this application.

Optionally, an interface between the second terminal device and the first terminal device is an edge link interface or a PC5 interface, for example, as shown in fig. 2 or fig. 3. The interface between the second terminal device and the radio access network device is an air interface, which may be an LTE air interface or an NR air interface, for example.

Optionally, the second terminal device detects signal quality between the second terminal device and the radio access network device, and generates the indication information when detecting that the signal quality between the second terminal device and the radio access network device is less than or equal to a preset threshold.

Specifically, the second terminal device may detect signal quality with the radio access network device, and generate and send the indication information to the first terminal device if it is detected that the signal quality does not meet a preset condition, for example, the signal quality is less than or equal to a preset threshold. That is to say, the second terminal device detects the signal quality, so that the terminal device with the relay function can be replaced in time, and the communication efficiency between the first terminal device and the access network device is prevented from being interrupted, thereby improving the communication efficiency.

Optionally, the second terminal device may also be the indication information generated when detecting that the signal quality between the second terminal device and the first terminal device is less than or equal to a preset threshold, which is not limited in this application.

Optionally, the second terminal device may also generate the indication information when a Radio Link Failure (RLF) is found to occur in the Radio access network, for example, the second terminal device finds that T310 is overtime due to degradation of a physical layer monitoring signal, or finds that a MAC layer random access fails, or finds that the number of retransmissions of the RLC layer data reaches the maximum number of retransmissions.

Optionally, the indication information may be carried in a PHY header or a MAC header of the user plane, or the indication information may be carried in a Sidelink Control Indicator (SCI) or a MAC Control Element (CE) of the control plane, so that the indication information is prevented from being separately transmitted, and signaling overhead is saved.

Alternatively, the indication information may directly indicate that the second terminal device stops providing the relay service for the first terminal device and the radio access network device.

Optionally, the indication information may also indirectly indicate that the second terminal device stops providing the relay service for the first terminal device and the radio access network device, for example, the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than or equal to a preset threshold, or the indication information indicates that the signal quality between the second terminal device and the first terminal device is less than or equal to a preset threshold, or the indication information indicates that a radio link failure occurs between the second terminal device and the radio access network device, that is, the second terminal device may flexibly select the indication manner. And when the first terminal receives the indirect indication, the first terminal learns that the second terminal equipment stops providing the relay service for the first terminal equipment and the wireless access network equipment.

402, the first terminal device sends notification information to the radio access network device through the third terminal device, where the notification information is used to instruct the first terminal device to connect to the radio access network device through the relay service of the third terminal device. Accordingly, the third terminal device receives the notification information from the first terminal device and forwards the notification information to the radio access network device. The radio access network device receives the notification information.

The first terminal device receives indication information indicating that the second terminal device stops providing relay service for the first terminal device from the second terminal device, then the first terminal device searches for a third terminal device, and then notification information is sent to the wireless access network device through the third terminal device and used for indicating that the first terminal device is connected to the wireless access network device through the relay of the third terminal device, so that the wireless access network device can communicate with the first terminal device through the third terminal device, the situation that the first terminal device suddenly finds that the second terminal device cannot relay the first terminal device, communication between the first terminal device and the wireless access network device is interrupted due to the fact that the first terminal device and the wireless access network device are in communication is avoided, and communication efficiency is improved.

Optionally, the indication information sent by the second terminal device to the first terminal device includes the identifier of the third terminal device, so that the first terminal device determines the third terminal device according to the identifier of the third terminal device, and sends the notification information to the radio access network device through the third terminal device. In other words, the first terminal device may not know the third terminal device to which to switch after receiving the indication information.

Optionally, the first terminal device may also determine a third terminal device in advance, for example, the first terminal device periodically searches for a relay device, or searches for a potential relay device when the signal quality between the first terminal device discovery and a currently serving relay device is lower than or equal to a certain threshold. The first terminal device initiates the change from the second terminal device to the third terminal device immediately after receiving the indication information.

In this embodiment, the "handover of a terminal device having a relay function" means that a first terminal device is connected to a radio access network device through a relay of a second terminal device, and is changed to a first terminal device connected to the radio access network device through a relay of a third terminal device.

Optionally, the first terminal device receives a relay notification message (relay notification) broadcasted by at least one relay device, where the relay notification message is used to indicate that the corresponding terminal device can provide a relay service for the first terminal device, and determines the third terminal device according to the at least one relay notification message.

Specifically, the first terminal device may search for a new relay device (which may be referred to as a "third terminal device" below) before performing handover of the terminal device having the relay function, for example, the first terminal device may search for a new relay device after receiving the indication information transmitted by the second terminal device. The first terminal device may passively receive at least one relay notification message sent by surrounding relay devices, that is, each relay device sends one relay notification message for indicating that it can provide a relay service for the first terminal device and the radio access network device. For example, the first terminal device searches the relay notification message in the receiving resource pool. It should be understood that a resource pool may be a frequency domain resource composed of one or more radio Resource Blocks (RBs), or a time-frequency domain resource composed of one or more RBs over a particular transmission time unit (e.g., 1 ms) or set of transmission time units. There may be one or more resource pools on each carrier. The receiving resource pool may be preset, or may be sent by the radio access network device to the first terminal device through broadcast (for example, physical broadcast channel PBCH) or RRC message. Thus, the first terminal device selects a target terminal device from the terminal devices corresponding to the at least one relay notification message as the third terminal device. The relay notification message may further carry a cell identifier, a radio access network device identifier, a Radio Access Technology (RAT) indicator (e.g., LTE or NR), a Timing Advance (TA) value, or a hop count between the first terminal device and the radio access device, so that the first terminal device may determine, according to the relay notification message, a more appropriate third terminal device to provide a relay service for the first terminal device, thereby further improving communication efficiency.

Optionally, an interface between the third terminal device and the first terminal device is a side link interface or a PC5 interface, and an interface between the third terminal device and the radio access network device is an LTE air interface or an NR air interface.

Optionally, the first terminal device actively discovers the relay device, for example, the first terminal device sends a relay discovery request message, where the relay discovery request message is used to seek a terminal device with a relay function, and receives a response message in response to the relay discovery request message, and determines the terminal device sending the response message as the third terminal device.

Specifically, the first terminal device may actively seek a new relay device (which may be referred to as a "third terminal device" below) before performing handover of the terminal device having the relay function, for example, the first terminal device may actively seek the new relay device after receiving the indication information. The first terminal device may broadcast the relay discovery request message, for example, transmitted in a transmission resource pool. Similarly, the transmission resource pool may be preset, or may be transmitted to the first terminal device by the base station through broadcast or RRC message. The relay discovery request message may carry a device identifier of the first terminal device and a device identifier of the radio access network device, after receiving the relay discovery request message, the terminal device having the relay function sends a response message to the first terminal device under the condition that the relay service can be provided for the first terminal device and the radio access network device, and the first terminal device takes the terminal device sending the response message as a third terminal device. If there are multiple terminal devices feeding back the response message, the first terminal device may select any one as the third terminal device.

Optionally, the response message further includes a cell identifier, a radio access network device, a RAT indicator, a TA value or a hop count, and the like, so that when the first terminal device receives multiple response messages, a third terminal device that is more suitable among the multiple terminal devices corresponding to the multiple response messages is selected to provide a relay service for the first terminal device, thereby further improving communication efficiency.

Optionally, the notification information further includes a device identifier of the first terminal device. It should be understood that the device identifier of the first terminal device may be a cell radio network temporary identifier (C-RNTI) of the first terminal device in a cell, a layer 2 (L2) identifier defined by a 3GPP standard (for example, an identifier that uniquely identifies the terminal device at the PC5 port), a MAC address, an IP address, or a local identifier allocated by a radio access network, which is not limited in this application.

Specifically, the radio access network device can know, according to the device identifier, that the terminal device with the relay function between the first terminal devices corresponding to the device identifier is switched, so that the radio access network device can accurately know which first terminal device the notification information is sent when a plurality of first terminal devices perform relay switching, and when the first terminal device performs communication, the switched terminal device is adopted, thereby improving communication efficiency.

In one embodiment, the notification information may be carried in an RRC message.

Specifically, the first terminal device may send an uplink RRC message to the third terminal device to carry the notification information, and accordingly, the third terminal device receives the RRC message, does not parse the RRC message, and directly forwards the RRC message to the radio access network device. For example, the RRC message may be called a relay addition (relay addition) or relay switch (relay switch) message.

When the first terminal equipment sends the notification information to the third terminal equipment, the notification information is taken as a load, an RLC header, an MAC header and a PHY header of a PC5 port are packaged outside the load, and a first instruction is added to the RLC/MAC/PHY header. The RLC header may be, for example, an RLC header defined in the standard, the MAC header may be, for example, a MAC header or a MAC subheader defined in the standard, and the PHY header may be, for example, a resource allocation header defined in the standard. Data is referred to as a Service Data Unit (SDU) of a particular protocol layer before it enters the layer for processing, and after processing (e.g., adding or encapsulating a header of the layer) is referred to as a Protocol Data Unit (PDU) of the layer. The header of each protocol layer mainly contains information related to the load, for example, the RLC layer header mainly contains information such as the type of data (indicating whether the data packet or the control packet), the sequence number, and the offset. The MAC header mainly includes information such as a logical channel number and a data length. For example, the notification information is an RLC SDU of the RLC layer, and an RLC header is added to the notification information to form an RLC PDU. The processing of other layers and so on. The first indication is used to indicate that the payload sent by the third terminal device at the PC5 port is an RRC message to the radio access network device. Or the first terminal equipment adds a first indication in the sidelink control information SCI before sending the notification information to the third terminal equipment. And after receiving the load, the third terminal equipment learns that the load is the RRC message sent to the radio access network equipment through the first indication. In addition, after receiving the RRC message from the first terminal device, the third terminal device removes the PHY/MAC/RLC of the sidelink/PC5 port, and sends the RRC message including the notification information to the radio access network device through a Signaling Radio Bearer (SRB) or a DRB channel between the third terminal device and the radio access network device, where the radio access network device obtains the notification information. And when the RRC message name is relay switch, the wireless access network equipment learns that the first terminal equipment finishes the switching from the second terminal equipment to the third terminal equipment according to the notification information. And when the RRC message name is relay addition, the wireless access network equipment learns that the third terminal equipment is added to the first terminal equipment as the relay equipment between the wireless access network equipment and the first terminal equipment according to the notification information.

Optionally, when the third terminal device forwards the RRC message, an adaptation layer may be further added on the LTE/NR air interface PHY/MAC/RLC, where the adaptation layer includes the device identifier of the first terminal device, so that after the radio access network device receives the RRC message, the radio access network device may remove the encapsulation of the LTE/NR air interface PHY/MAC/RLC to obtain the device identifier of the first terminal device, and when the radio access network device obtains the device identifier of the first terminal device, the radio access network device may know that the first terminal device is connected to the radio access network device through the relay of the second terminal device and is changed to be connected to the radio access network device through the relay of the third terminal device.

It should be understood that the radio access network device may further send the RRC message to the PDCP entity corresponding to SRB1 of the first terminal device after detecting that the first terminal device having corresponding to the first terminal device identity has established an RRC connection.

Optionally, the third terminal device adds an adaptation layer on the RLC, and in order to make the radio access network device know that the adaptation layer is also included on the RLC, the third terminal device may further send indication information to indicate that the adaptation layer exists.

In another embodiment, the notification information may also be carried on a PHY/MAC/PHY header of the PC5 port, and after obtaining the notification information, the third terminal device sends a first message to the radio access network device, where the first message is used to notify the radio access network device that the third terminal device is used as a relay device between the first terminal device and the radio access network device. For example, the first message may be an uplink RRC message generated by the third terminal device. The first message may contain an identification of said first terminal device. The first message may imply an indication, or may carry a displayed indication to notify the radio access network device that the third terminal device is connected to the radio access network device as a relay of the first terminal device. For example, the first message is named relay addition, or a cell containing relay addition is included in the first message. And when the RRC message name is relay switch, the wireless access network equipment learns that the first terminal equipment completes the switching from the second terminal equipment to the third terminal equipment according to the notification information. And when the RRC message name is relay addition, the wireless access network equipment learns that the third terminal equipment is added to the first terminal equipment as the relay equipment between the wireless access network equipment and the first terminal equipment according to the notification information.

Optionally, the second terminal device may send the signal to be transmitted of the first terminal device to the third terminal device. The signal to be transmitted may be a downlink signal that is sent by the second terminal device to the first terminal device but has not been sent to the first terminal device or is sent to the first terminal device unsuccessfully, or an uplink signal that is sent by the second terminal device to the radio access network device but has not been sent to the radio access network device or is sent to the radio access network device unsuccessfully.

Specifically, the second terminal device may forward the to-be-transmitted signal of the first terminal device, which is sent to the radio access network device, through the third terminal device. Or the second terminal device can forward the signal to be transmitted sent to the first terminal device through the third terminal device, so that data loss caused by switching of the terminal device with the relay function is avoided, and the signal quality is improved.

It should be noted that the signal to be transmitted may be a signal of the first terminal device that fails to be sent after being sent by the second terminal device, or may also be a signal of the first terminal device that has not been forwarded by the second terminal device, which is not limited in this application.

It should be understood that the signal to be transmitted may be a downlink signal or an uplink signal. The downlink signal may be data or signaling, which is not limited in this application. The uplink signal may be data, signaling, or the like, and the present application does not limit this, and the following embodiments describe data as an example.

Optionally, the first terminal device receives a PDCP status report from the radio access network device, where the PDCP status report is used to indicate whether the radio access network device successfully receives the uplink PDCP data. After receiving the PDCP status report of the radio access network device, the first terminal device retransmits the data with transmission failure to the radio access network device through the third terminal device when the PDCP status report indicates reception failure.

Specifically, the radio access network device feeds back a PDCP status report periodically, and the PDCP status report includes a packet loss condition. For example, the PDCP status report includes a first missing PDCP Sequence Number (SN) number and a bitmap (bitmap) whose value indicates whether each of the subsequent PDCP SNs starting from the first missing packet sequence number (FMS) is missing. And the first terminal equipment retransmits the uplink data which is failed to be transmitted by the second terminal equipment to the wireless access network equipment through the third terminal equipment according to the PDCP status report.

Optionally, the radio access network device receives a PDCP status report from the first terminal device, where the PDCP status report is used to indicate whether the first terminal device successfully receives downlink PDCP data. After receiving the PDCP status report of the first terminal device, the radio access network device retransmits the downlink data to the first terminal device through the third terminal device when the PDCP status report indicates a reception failure.

Specifically, the first terminal device may also periodically feed back a PDCP status report, which is similar to the PDCP status report described above, so that the radio access network device may determine whether data is successfully received according to the PDCP status report, and resend the first data to the first terminal device through the third terminal device when the PDCP status report indicates that data reception fails.

Optionally, the second terminal device determines a second channel identifier according to a first channel carrying the uplink signal and the first mapping relationship, and sends the uplink data received through the first channel to the third terminal device through a channel corresponding to the second channel identifier, and then the uplink data is sent to the radio access network device by the third terminal device, where the first mapping relationship is a mapping relationship in which at least one first channel identifier and at least one second channel identifier correspond to each other one by one.

Specifically, the first mapping relationship is a one-to-one mapping relationship between at least one first channel identifier and at least one second channel identifier. The first channel identifier may be a bearer identifier of the first terminal device, the second channel identifier may be a second logical channel identifier, a bearer corresponding to the bearer identifier of the first terminal device may be used for communication between the first terminal device and the radio access network device, and a logical channel corresponding to the second logical channel identifier may be used for communication between the second terminal device and the third terminal device. The bearers between the first terminal device and the radio access network device may be 1 or more, and the logical paths between the second terminal device and the third terminal device may also be 1 or more. The second terminal device receives the uplink data from the first terminal device, and according to the bearer identifier of the first terminal device bearing the uplink data (the following identifier is the bearer identifier of the first terminal device), and in combination with the first mapping relationship, can determine to send the uplink data on a specific second logical channel of the plurality of second logical channels, so that the second terminal device regularly sends the uplink data which is not successfully sent to the third terminal device through the second logical channel, so that the third terminal device subsequently forwards the data to the radio access network device, the problem of packet loss caused by the change of the terminal device with the relay function is avoided, and the communication efficiency is improved.

It should be noted that, if the bearer identifiers of different first terminal devices are respectively numbered independently, the second terminal device may determine the corresponding bearer according to the identifier of the first terminal device and the bearer identifier of the first terminal device. For example, the second relay device receives an RRC configuration message sent by the radio access network device, where the RRC configuration message includes an identifier of the first terminal device, and a mapping relationship between a bearer identifier of the first terminal and the sixth channel identifier. The sixth channel may be a transmission channel between the first terminal device and the second terminal device, and the sixth channel identifier may be a logical channel identifier used for transmitting data in the transmission channel. And the second terminal equipment receives the data from the first terminal equipment through the sixth channel and acquires the logical channel identifier of the corresponding sixth channel. And then the second terminal equipment acquires the corresponding bearing identification of the first terminal equipment according to the logical channel identification and the mapping relation.

It is to be understood that the bearer in the embodiment of the present application may be an SRB, or a DRB, without being particularly described. In the embodiment of the present application, a channel between terminal devices having a relay function or a channel between a first terminal device and a terminal device having a relay function may be a logical channel, and the following embodiment takes the logical channel as an example for description, which is not limited in the present application.

Optionally, the second terminal device determines a second channel identifier according to a third channel carrying the downlink signal, the first mapping relationship and a second mapping relationship, and sends the downlink data received through the third channel to the third terminal device through the second channel corresponding to the second channel identifier, and then the downlink data is sent to the first terminal device by the third terminal device, where the first mapping relationship is a one-to-one mapping relationship between at least one first channel identifier and at least one second channel identifier, and the second mapping relationship is a one-to-one mapping relationship between at least one third channel identifier and at least one first channel identifier.

Specifically, the first channel identifier may be a bearer identifier of the first terminal device, the second channel identifier may be a second logical channel identifier, the third channel identifier may be a bearer identifier of the second terminal device, a bearer corresponding to the bearer identifier of the first terminal device may be used for communication between the first terminal device and the radio access network device, a logical channel corresponding to the second logical channel identifier may be used for communication between the second terminal device and the third terminal device, and a bearer corresponding to the bearer identifier of the second terminal device may be used for communication between the second terminal device and the radio access network device. The number of bearers between the first terminal device and the radio access network device may be 1 or more, the number of logical channels between the second terminal device and the third terminal device may be 1 or more, and the number of bearers between the second terminal device and the radio access network device may be 1 or more. The second terminal device receives downlink data from the radio access network device, the downlink data is borne on a third channel (namely, the second terminal device bears the load), the second terminal device determines the bearing identifier of the first terminal device corresponding to the third channel identifier according to the third channel and the third mapping relation, then determines the second channel identifier (namely, the second logic channel identifier) according to the bearing identifier of the first terminal device and the first mapping relation, and further bears the downlink data on a second logic channel corresponding to the second logic channel identifier, so that the second terminal device regularly sends unsuccessfully sent downlink signals to the third terminal device through the second logic channel, and the second terminal device forwards the unsuccessfully sent downlink signals to the first terminal device, the packet loss problem caused by the change of the terminal device with the relay function is avoided, and the communication efficiency is improved.

Optionally, the first mapping relationship may be determined by the second terminal device and sent to the third terminal device; or the first mapping relation is determined for the radio access network device and is respectively sent to the second terminal device and the third terminal device.

Optionally, the radio access network device may send the first mapping relationship only to the second terminal device, and the second terminal device sends the first mapping relationship to the third terminal device. Specifically, the second terminal device may send the SCI to the third terminal device, where the SCI carries the first mapping relationship, so as to avoid sending the first mapping relationship separately, and save signaling overhead.

Optionally, the second mapping relationship may be sent by the radio access network device to the second terminal device.

Optionally, the third terminal device may determine the fourth channel according to the second logical channel identifier, the first mapping relationship and a third mapping relationship, where the first mapping relationship is a one-to-one mapping relationship between at least one first channel identifier and at least one second channel identifier, and the third mapping relationship is a mapping relationship between at least one fourth channel identifier and at least one first channel identifier.

Specifically, when the second terminal device sends uplink data to be sent to the radio access network device, the second terminal device may send the uplink data to the third terminal device, and the third terminal device forwards the uplink data number to the radio access network device. The fourth channel is a channel between the third terminal device and the radio access network device, and when the first channel identifier is a bearer identifier of the first terminal device and the fourth channel identifier is a bearer identifier of the third terminal device, the first mapping relationship is a mapping relationship in which at least one bearer identifier of the first terminal device and at least one second logical channel identifier correspond to each other one by one, and the third mapping relationship is a mapping relationship in which at least one bearer identifier of the third terminal device and at least one bearer identifier of the first terminal device correspond to each other one by one. Therefore, the third terminal device can determine the bearing identifier of the first terminal device according to the second logical channel identifier and the first mapping relationship, then determine the bearing identifier of the third terminal device according to the bearing identifier of the first terminal device and the third mapping relationship, and then send the uplink data to the radio access network device through the bearing corresponding to the bearing identifier of the third terminal device, thereby improving the communication efficiency.

Optionally, the third terminal device may determine the fifth channel according to the second channel identifier, the first mapping relationship and a fourth mapping relationship, where the first mapping relationship is a one-to-one mapping relationship between at least one first channel identifier and at least one second channel identifier, and the fourth mapping relationship is a one-to-one mapping relationship between at least one fifth channel identifier and at least one first channel identifier.

Specifically, when the second terminal device sends downlink data to the first terminal device, the third terminal device may determine the fifth channel according to the second channel, the first mapping relationship, and the fourth mapping relationship. The fifth channel is used for the first terminal device to communicate with the third terminal device, and the fifth channel may be a fifth logical channel. And under the condition that the first channel identifier is the bearer identifier of the first terminal device, the first mapping relationship is a one-to-one mapping relationship between the bearer identifier of at least one first terminal device and at least one second logical channel identifier, and the fourth mapping relationship is a one-to-one mapping relationship between at least one fifth logical channel identifier and the bearer identifier of at least one first terminal device. Therefore, the third terminal device can determine the bearer identifier of the first terminal device according to the second logical channel and the first mapping relationship, determine the fifth logical channel identifier according to the bearer identifier of the first terminal device and the fourth mapping relationship, and send downlink data to the first terminal device through the logical channel corresponding to the fifth logical channel identifier, so that the communication efficiency is improved.

Optionally, the third mapping relation or the fourth mapping relation may be determined and sent by the radio access network device to the third terminal device.

Optionally, the third mapping relationship or the fourth mapping relationship may also be carried in an RRC reconfiguration message.

Optionally, after the first terminal device is switched from the second terminal device to the third terminal device, the uplink signal or the downlink signal that is not forwarded by the second terminal device may be forwarded by the third terminal device. Specifically, the radio access network device may perform downlink data retransmission, and the first terminal device performs uplink data retransmission; or the wireless access network equipment retransmits the downlink data, and the second terminal equipment retransmits the uplink data (namely the second terminal equipment forwards the uplink data to the third terminal equipment, and the third terminal equipment transmits the uplink data to the wireless access network equipment); or the second terminal device retransmits the downlink data (that is, the second terminal device retransmits the downlink data to the third terminal device and transmits the downlink data to the first terminal device through the third terminal device), and the first terminal device retransmits the uplink data; or the second terminal equipment performs downlink data retransmission, and the second terminal equipment performs uplink data retransmission.

In an embodiment of the present application, a first terminal device determines a fourth terminal device, where the fourth terminal device is a relay device capable of providing a relay service for the first terminal device and the radio access network device together with the second terminal device or the third terminal device, and the first terminal device sends notification information, through the fourth terminal device, to the radio access network device, where the notification information is used to indicate that the fourth terminal device is capable of providing the relay service for the first terminal device and the radio access network device together with the second terminal device or the third terminal device.

Specifically, when the first terminal device finds that the fourth terminal device can also provide the relay service for the first terminal device and the wireless radio access network device, the first terminal device may add the relay device (relay addition), that is, the first terminal device establishes the relay multi-connection. For example, the first terminal device may respectively establish a connection with a fourth terminal device serving as the relay device and a second terminal device serving as the relay device at the same time, or the first terminal device may respectively establish a connection with the fourth terminal device and a third terminal device at the same time, and notify the radio access network device through the fourth terminal device, so that the radio access network device may simultaneously send downlink data to the first terminal device through the second terminal device and the fourth terminal device, or simultaneously send downlink data to the first terminal device through the third terminal device and the fourth terminal device, thereby improving communication efficiency.

It should be noted that, if it is the second terminal device that currently provides the relay service for the first terminal device and the radio access network device, after the fourth terminal device is added, the second terminal device and the fourth terminal device simultaneously provide the relay service for the first terminal device and the radio access network device. If the third terminal device is currently providing the relay service for the first terminal device and the wireless access network device, after the fourth terminal device is added, the third terminal device and the fourth terminal device simultaneously provide the relay service for the first terminal device and the wireless access network device.

Fig. 6 shows a schematic flow chart of a method of relaying communication according to another embodiment of the present application.

It should be noted that the embodiment shown in fig. 6 has the same meaning as that of the embodiment described above, except for the specific description.

601, a first terminal device receives indication information, where the indication information is used to indicate that a second terminal device needs to be replaced by the first terminal device, the second terminal device is a device that currently provides a relay service for the first terminal device, and the indication information carries at least one terminal device that the first terminal device can replace. Accordingly, the radio access network device transmits the indication information.

Specifically, the second terminal device is a device that currently provides a relay service for communication between the first terminal device and the radio access network, the indication information carries at least one terminal device that can be replaced by the first terminal device, and the at least one terminal device may be carried in the indication information in a form of a list.

Optionally, an interface of the first terminal device for communicating with the second terminal device is a PC5 interface or an edge link interface.

Specifically, the interface of the second terminal device with the first terminal device is an edge link interface or a PC5 interface, for example, as shown in fig. 2 or fig. 3, in other words, the second terminal device may be a terminal device type device. The interface between the second terminal device and the radio access network device is an air interface, which may be an LTE air interface or an NR air interface, for example.

Optionally, the radio access network device detects a signal quality between the first terminal device and the second terminal device, and generates the indication information when the signal quality between the first terminal device and the second terminal device is less than or equal to a first preset threshold.

Specifically, when the radio access network device detects that the signal quality between the first terminal device and the second terminal device is poor, for example, the radio access network device learns the signal quality between the second terminal device and the first terminal device from the second terminal device, or obtains the signal quality between the second terminal device and the first terminal device through measurement of the first terminal device forwarded by the second terminal device.

Optionally, the radio access network device detects signal quality between the radio access network device and the second terminal device, and generates the indication information when the signal quality between the radio access network device and the second terminal device is less than or equal to a second preset threshold.

Specifically, the radio access network device detects that a signal between the radio access network device and the second terminal device is poor, for example, the radio access network device measures the quality of an uplink signal (sounding reference signal (SRS)) of the second terminal device, or a measurement report of layer 3 defined by a 3GPP standard reported by the second terminal device (e.g., reference Signal Received Power (RSRP) or Reference Signal Received Quality (RSRQ)), or a Channel State Information (CSI) feedback of layer 2 (e.g., channel Quality Indicator (CQI)/Precoding Matrix Indicator (PMI)/Rank Indication (RI)).

It is to be understood that layer 2 may be at least one of a MAC layer, RCL layer, PDCP layer, or adaptation layer; layer 3 may be the RRC layer or a layer above the RRC layer, such as the IP layer, UDP layer/TCP layer, or application layer.

Optionally, if a direct air interface (e.g., an in-cell coverage (ICC) scenario) exists between the radio access network device and the first terminal device, the radio access network device may directly send the indication information to the first terminal device. For example, the radio access network device may carry the indication information through an RRC reconfiguration message.

Optionally, the radio access network device may send the indication information to the first terminal device through the second terminal device. For example, an Out of Cell Coverage (OCC) scenario. The radio access network device may also send an RRC reconfiguration message to the first terminal device through the second terminal device, where the RRC reconfiguration message carries the indication information.

And 602, the first terminal device determines a third terminal device from the at least one terminal device according to the indication information.

Specifically, an interface between the third terminal device and the first terminal device is also a PC5 interface (or called an edge link interface), and an interface between the third terminal device and the radio access network device may be an LTE air interface or an NR air interface.

Optionally, the first terminal device performs a handover from the second terminal device to a third terminal device.

In particular, the handover may be understood as the switching of the first terminal device from accessing the access network device by the second terminal device to accessing the access network device by the third terminal device.

603, the first terminal device sends notification information to the radio access network device through the third terminal device, where the notification information is used to instruct the first terminal device to connect to the radio access network device through the third terminal device.

Specifically, the first terminal device receives indication information sent by the radio access network device and used for indicating that the first terminal device needs to replace the second terminal device, and the indication information also carries at least one replaceable terminal device, so that the first terminal device can select a proper third terminal device according to the indication information, the first terminal device is prevented from actively searching for the proper third terminal device, the power consumption of the first terminal device is saved, communication is performed through the proper third terminal device, and the communication efficiency of the first terminal device and the radio access network device is also improved.

Fig. 7 shows a schematic flow chart of relay communication according to another embodiment of the present application.

It should be understood that the same terms as those in the above-described embodiments in the embodiments of the present application have the same meanings, unless otherwise specified.

It should also be understood that the embodiments of the present application can be implemented alone, and can be combined with any combinable scheme described above, which is not limited in the present application.

It should be noted that the embodiment of the present application is applied to a communication system including a first terminal device, a second terminal device, a third terminal device and a radio access network device, where the third terminal device is a device that currently provides a relay service for the first terminal device and the radio access network device, and the second terminal device is a device that provides a relay service for the first terminal device and the radio access network device before the third terminal device.

701, the second terminal device receives data belonging to the first terminal device.

Specifically, the data belonging to the first terminal device may be data that the second terminal device has not successfully forwarded, or may be data that has not been forwarded. In addition, the data of the first terminal device may be uplink data or downlink data, which is not limited in this application.

And 702, the second terminal device sends a first message to the third terminal device, where the first message includes data of the first terminal device and notification information, the notification information is used to indicate an identifier of the first terminal device, a DRB identifier for data radio bearer, and direction indication information, the DRB identifier is used to indicate a DRB between the first terminal device and the radio access network device, and the direction indication information is used to indicate a transmission direction of the data of the first terminal device.

Specifically, there may be a plurality of bearers for performing communication between the first terminal device and the radio access network device, where the bearer may be a DRB, where the first message carries a bearer identifier corresponding to certain data (hereinafter, referred to as data of the first terminal device) of the first terminal device, an identifier of the first terminal device, and direction indication information, and the direction indication information may indicate whether the data belonging to the first terminal device is uplink data or downlink data. And if the data is the uplink data, the third relay equipment forwards the data to the wireless access network equipment subsequently. And if the data is downlink data, the third relay equipment forwards the data to the first terminal equipment subsequently. In addition, the data and the notification information of the first terminal device may be carried in the same message (i.e., the first message), so that the third terminal device can know, when receiving the first message, which terminal device the data included in the first message is, and the DRB identifier corresponding to the data of the first terminal device, so that the third terminal device can accurately determine, according to the first message, to which receiving end the data of the first terminal device is sent (e.g., to which channel between the third terminal device and the radio access network device the uplink data is sent, and to which channel between the third terminal device and the radio access network device the downlink data is sent), and which channel is used (i.e., to which channel between the third terminal device and the radio access network device, or to which channel between the third terminal device and the first terminal device), thereby improving communication efficiency.

In an embodiment, the notification information may be carried in the SCI, so that the SCI and the data of the first terminal device may be in the same message, and the time for transmitting the SCI and the data of the first terminal device may be the same or different, for example, the time domain resource for transmitting the SCI precedes the time domain resource for transmitting the data of the first terminal device.

It should be understood that the time domain resource may be in units of at least one time domain symbol, where 12 or 14 time domain symbols constitute one transmission time unit, and this time transmission unit occupies 1ms in LTE, referred to as one subframe including two slots, and also occupies 1ms in NR, but referred to as one slot, which is not limited in this application.

In another embodiment, the notification information may be carried in an adaptation layer in the first message. For example, when the second relay device sends the data belonging to the first terminal device to the third relay device, the adaptation layer header, the RLC header, the MAC header, and the PHY header of the PC5 interface are encapsulated outside the data, and the adaptation layer includes the identifier of the first terminal device, the bearer identifier of the first terminal device, and the direction indication information. Specifically, the direction indication information may be UL or DL indication, or may be UL if carrying the direction indication information and DL if not carrying the direction indication information. Or when carrying the direction indication information, it is indicated as DL, and when not carrying the direction indication information, it is indicated as UL.

Specifically, the second terminal device may encapsulate the data of the first terminal device and the notification information through the adaptation layer to obtain the first message, and send the first message to the third terminal device, and the third terminal device obtains the notification information through parsing in the adaptation layer.

In another embodiment, the notification information may be carried in the MAC layer or other layer in the first message.

Having described the method of relaying communication in detail above according to the embodiments of the present application, an apparatus of relaying communication of the embodiments of the present application will be described below.

Fig. 8 shows a schematic block diagram of an apparatus 800 for relaying communication according to an embodiment of the present application.

It is to be understood that the apparatus 800 may correspond to the terminal device in the embodiment shown in fig. 4, and may have any function of the first terminal device in the method. The apparatus 800 includes a receiving module 810 and a transmitting module 820.

A receiving module 810, configured to receive indication information from the second terminal device, where the indication information is used to indicate that the relay service between the first terminal device and the radio access network device stops being provided;

the sending module 820 is further configured to send notification information to the radio access network device through a third terminal device, where the notification information indicates that the first terminal device is connected to the radio access network device through the third terminal device.

Optionally, the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than or equal to a preset quality threshold.

Optionally, the indication information indicates that a radio link failure occurs between the second terminal device and the radio access network device.

Optionally, the indication information further indicates an identifier of the third terminal device, and the apparatus 800 further includes a processing module 830, where the processing module 830 is configured to determine the third terminal device according to the identifier of the third terminal device.

Optionally, the notification information further indicates an identifier of the first terminal device.

Optionally, the sending module 810 is further configured to send the identifier of the third terminal device to the second terminal device.

Fig. 9 shows a schematic block diagram of an apparatus 900 for relaying communication according to an embodiment of the present application, where the apparatus 900 may be the terminal device described in fig. 1 and the terminal device described in fig. 4. The apparatus may employ a hardware architecture as shown in fig. 9. The apparatus may include a processor 910 and a transceiver 920, and optionally, the apparatus may further include a memory 930, the processor 910, the transceiver 920, and the memory 930 being in communication with each other via an internal connection path. The related functions implemented by the processing module 830 in fig. 8 can be implemented by the processor 910, and the related functions implemented by the receiving module 810 and the transmitting module 820 can be implemented by the processor 910 controlling the transceiver 920.

Alternatively, the processor 910 may be a general processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), a special-purpose processor, or one or more ics for executing the embodiments of the present application. Alternatively, a processor may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions). For example, a baseband processor, or a central processor. The baseband processor may be configured to process communication protocols and communication data, and the central processor may be configured to control a device (e.g., a base station, a terminal device, or a chip) that relays communication, execute a software program, and process data of the software program.

Optionally, the processor 910 may include one or more processors, for example, one or more Central Processing Units (CPUs), and in the case that the processor is a CPU, the CPU may be a single-core CPU, or a multi-core CPU.

The transceiver 920 is used for transmitting signals and receiving signals. The transceiver may include a transmitter for transmitting signals and a receiver for receiving signals. It should be understood that the signals may be data and/or signaling.

The memory 930 includes, but is not limited to, a Random Access Memory (RAM), a read-only memory (ROM), an Erasable Programmable Read Only Memory (EPROM), and a compact disc read-only memory (CD-ROM), and the memory 930 is used for storing relevant instructions and data.

The memory 930 is used for storing program codes and data of the terminal device, and may be a separate device or integrated in the processor 910.

Specifically, the processor 910 is configured to control the transceiver to perform information transmission with the radio access network device. Specifically, reference may be made to the description of the method embodiment, which is not repeated herein.

It will be appreciated that fig. 9 only shows a simplified design of the means for relaying communication. In practical applications, the apparatus may also include other necessary elements respectively, including but not limited to any number of transceivers, processors, controllers, memories, etc., and all terminal devices that can implement the present application are within the protection scope of the present application.

In one possible design, the apparatus 900 may be a chip, for example, a communication chip that may be used in a terminal device, and is used to implement the relevant functions of the processor 910 in the terminal device. The chip can be a field programmable gate array, a special integrated chip, a system chip, a central processing unit, a network processor, a digital signal processing circuit and a microcontroller which realize related functions, and can also adopt a programmable controller or other integrated chips. The chip may optionally include one or more memories for storing program code that, when executed, causes the processor to implement corresponding functions.

In particular implementations, apparatus 900 may also include an output device and an input device, as one embodiment. An output device, which is in communication with the processor 910, may display information in a variety of ways. For example, the output device may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device is in communication with the processor 801 and may receive user input in a variety of ways. For example, the input device may be a mouse, a keyboard, a touch screen device, a sensing device, or the like.

Fig. 10 shows a schematic block diagram of an apparatus 1000 for relaying communication according to an embodiment of the present application.

It is to be understood that the apparatus 1000 may correspond to the terminal device in the embodiment shown in fig. 4, and may have any function of the second terminal device in the method. The apparatus 1000 includes a processing module 1010 and a transmitting module 1020.

A processing module 1010, configured to generate indication information, where the indication information is used to indicate that the relay service between the first terminal device and the radio access network device is stopped to be provided;

a sending module 1020, configured to send the indication information to the first terminal device.

Optionally, the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than a preset threshold.

Optionally, the sending module 1020 is further configured to send data to be sent of the first terminal device to a third terminal device, where the third terminal device is a device that currently provides a relay service for the first terminal device and the radio access network device, and the second terminal device is a device that previously provides a relay service for the first terminal device and the radio access network device.

Optionally, the sending module 1020 is specifically configured to:

and sending a first message, wherein the first message comprises the data to be sent, and the first message further comprises an identifier of the first terminal device, an identifier of a first channel and transmission direction indication information, and the first channel is used for communication between the first terminal device and the radio access network device.

Fig. 11 shows an apparatus 1100 for relaying communication according to an embodiment of the present application, where the apparatus 1100 may be the second terminal device shown in fig. 4. The apparatus may employ a hardware architecture as shown in fig. 11. The apparatus may include a processor 1110 and a transceiver 1120, and optionally, the apparatus may further include a memory 1130, the processor 1110, the transceiver 1120, and the memory 1130 communicating with each other through an internal connection path. The related functions implemented by the processing module 1010 in fig. 10 may be implemented by the processor 1110, and the related functions implemented by the transmitting module 1020 may be implemented by the processor 1110 controlling the transceiver 1120.

Alternatively, the processor 1110 may be a general processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), a special-purpose processor, or one or more ics for executing embodiments of the present application. Alternatively, a processor may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions). For example, a baseband processor, or a central processor. The baseband processor may be configured to process communication protocols and communication data, and the central processor may be configured to control a device (e.g., a base station, a terminal device, or a chip) that relays communication, execute a software program, and process data of the software program.

Optionally, the processor 1110 may include one or more processors, for example, one or more Central Processing Units (CPUs), and in the case that the processor is one CPU, the CPU may be a single-core CPU, or a multi-core CPU.

The transceiver 1120 is used for transmitting signals and receiving signals. The transceiver may include a transmitter for transmitting signals and a receiver for receiving signals.

The memory 1130 includes, but is not limited to, a Random Access Memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM), and a compact disc read-only memory (CD-ROM), and is used for storing relevant instructions and data.

The memory 1130 is used for storing program codes and data of the terminal device, and may be a separate device or integrated in the processor 1110.

Specifically, the processor 1110 is configured to control the transceiver to perform information transmission with the radio access network device. For details, reference may be made to the description in the method embodiments, which are not repeated herein.

In particular implementations, apparatus 1100 may also include an output device and an input device, as an example. An output device is in communication with processor 1110 and may display information in a variety of ways. For example, the output device may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device is in communication with the processor 801 and may receive user input in a variety of ways. For example, the input device may be a mouse, a keyboard, a touch screen device, a sensing device, or the like.

It will be appreciated that fig. 11 only shows a simplified design of the means for relaying communication. In practical applications, the apparatus may also include other necessary elements respectively, including but not limited to any number of transceivers, processors, controllers, memories, etc., and all terminal devices that can implement the present application are within the protection scope of the present application.

In one possible design, the apparatus 1100 may be a chip, such as a communication chip that may be used in a terminal device, for implementing the relevant functions of the processor 1110 in the terminal device. The chip can be a field programmable gate array, a special integrated chip, a system chip, a central processing unit, a network processor, a digital signal processing circuit and a microcontroller which realize related functions, and can also adopt a programmable controller or other integrated chips. The chip may optionally include one or more memories for storing program code that, when executed, causes the processor to implement corresponding functions.

The embodiment of the application also provides a device which can be terminal equipment or a circuit. The apparatus may be configured to perform the actions performed by the terminal device in the above method embodiments.

Fig. 12 shows a schematic block diagram of an apparatus 1200 for relaying communication according to an embodiment of the present application.

It is to be understood that the apparatus 1200 may correspond to the terminal device in the embodiment shown in fig. 7, and may have any function of the second terminal device in the method. The apparatus 1200 includes a receiving module 1210 and a transmitting module 1220.

It should be noted that the apparatus 1200 is applied to a communication system including a first terminal device, the apparatus 1200, a third terminal device and a radio access network device, where the third terminal device is a device that currently provides a relay service for the first terminal device and the radio access network device, and the second terminal device is a device that provides a relay service for the first terminal device and the radio access network device before the third terminal device, and the apparatus 1200 includes:

the receiving module 1210 is configured to receive data belonging to the first terminal device;

the sending module 1220 is further configured to send a first message to the third terminal device, where the first message includes the data belonging to the first terminal device and notification information, the notification information is used to indicate an identifier of the first terminal device, a DRB identifier of a data radio bearer, and direction indication information, the DRB identifier is used to identify a DRB carrying the data between the first terminal device and the radio access network device, and the direction indication information is used to indicate a transmission direction of the data.

Optionally, the notification information is carried in sidelink control information SCI, where a time domain resource of the SCI is the same as a time domain resource of the data belonging to the first terminal device, or is before the time domain resource of the data belonging to the first terminal device.

Optionally, the notification information is carried in an adaptation layer of the first message.

Fig. 13 shows an apparatus 1300 for relaying communication according to an embodiment of the present application, where the apparatus 1300 may be the second terminal device shown in fig. 7. The apparatus may employ a hardware architecture as shown in fig. 13. The apparatus may include a processor 1310 and a transceiver 1320, and optionally, the apparatus may further include a memory 1330, the processor 1310, the transceiver 1320, and the memory 1330 communicating with each other through an internal connection path. The required processing-related functions of fig. 10 may be implemented by the processor 1310, and the related functions implemented by the receiving module 1010 and the transmitting module 1020 may be implemented by the processor 1310 controlling the transceiver 1320.

Alternatively, the processor 1310 may be a general processing unit (CPU), a microprocessor, an application-specific integrated circuit (ASIC), a special-purpose processor, or one or more integrated circuits for performing the embodiments of the present application. Alternatively, a processor may refer to one or more devices, circuits, and/or processing cores for processing data (e.g., computer program instructions). For example, a baseband processor, or a central processor. The baseband processor may be configured to process communication protocols and communication data, and the central processor may be configured to control a device (e.g., a base station, a terminal device, or a chip) that relays communication, execute a software program, and process data of the software program.

Optionally, the processor 1310 may include one or more processors, for example, one or more Central Processing Units (CPUs), and in the case that the processor is one CPU, the CPU may be a single-core CPU or a multi-core CPU.

The transceiver 1320 is used to transmit signals as well as receive signals. The transceiver may include a transmitter for transmitting signals and a receiver for receiving signals.

The memory 1330 includes, but is not limited to, a Random Access Memory (RAM), a read-only memory (ROM), an Erasable Programmable Read Only Memory (EPROM), a compact disc read-only memory (CD-ROM), and the memory 1330 is used for storing relevant instructions and data.

The memory 1330 is used for storing program codes and data of the terminal device, and may be a separate device or integrated in the processor 1310.

Specifically, the processor 1310 is configured to control the transceiver to perform information transmission with the radio access network device. Specifically, reference may be made to the description of the method embodiment, which is not repeated herein.

In particular implementations, apparatus 1300 may also include an output device and an input device, as an embodiment. An output device, which is in communication with the processor 1310, may display information in a variety of ways. For example, the output device may be a Liquid Crystal Display (LCD), a Light Emitting Diode (LED) display device, a Cathode Ray Tube (CRT) display device, a projector (projector), or the like. The input device is in communication with the processor 801 and may receive user input in a variety of ways. For example, the input device may be a mouse, a keyboard, a touch screen device, or a sensing device, among others.

It will be appreciated that fig. 13 merely shows a simplified design of an apparatus for relaying communications. In practical applications, the apparatus may also include other necessary elements respectively, including but not limited to any number of transceivers, processors, controllers, memories, etc., and all terminal devices that can implement the present application are within the protection scope of the present application.

In one possible design, the apparatus 1300 may be a chip, such as a communication chip that may be used in a terminal device, and is used to implement the relevant functions of the processor 1310 in the terminal device. The chip can be a field programmable gate array, a special integrated chip, a system chip, a central processing unit, a network processor, a digital signal processing circuit and a microcontroller which realize related functions, and can also adopt a programmable controller or other integrated chips. The chip may optionally include one or more memories for storing program code that, when executed, causes the processor to implement corresponding functions.

Optionally, when the apparatus in this embodiment is a terminal device, fig. 14 shows a schematic structural diagram of a simplified terminal device. For ease of understanding and illustration, in fig. 14, the terminal device is exemplified by a mobile phone. As shown in fig. 14, the terminal device includes a processor, a memory, a radio frequency circuit, an antenna, and an input-output device. The processor is mainly used for processing communication protocols and communication data, controlling the terminal equipment, executing software programs, processing data of the software programs and the like. The memory is used primarily for storing software programs and data. The radio frequency circuit is mainly used for converting baseband signals and radio frequency signals and processing the radio frequency signals. The antenna is mainly used for receiving and transmitting radio frequency signals in the form of electromagnetic waves. Input and output devices, such as touch screens, display screens, keyboards, etc., are used primarily for receiving data input by a user and for outputting data to the user. It should be noted that some kinds of terminal devices may not have input/output devices.

When data needs to be sent, the processor performs baseband processing on the data to be sent and outputs baseband signals to the radio frequency circuit, and the radio frequency circuit performs radio frequency processing on the baseband signals and sends the radio frequency signals to the outside in the form of electromagnetic waves through the antenna. When data is sent to the terminal equipment, the radio frequency circuit receives radio frequency signals through the antenna, converts the radio frequency signals into baseband signals and outputs the baseband signals to the processor, and the processor converts the baseband signals into the data and processes the data. For ease of illustration, only one memory and processor are shown in FIG. 14. In an actual end device product, there may be one or more processors and one or more memories. The memory may also be referred to as a storage medium or a storage device, etc. The memory may be provided independently of the processor, or may be integrated with the processor, which is not limited in this embodiment of the present application.

In the embodiment of the present application, the antenna and the radio frequency circuit having the transceiving function may be regarded as a transceiving unit of the terminal device, and the processor having the processing function may be regarded as a processing unit of the terminal device. As shown in fig. 14, the terminal device includes a transceiving unit 1410 and a processing unit 1420. A transceiver unit may also be referred to as a transceiver, a transceiving device, etc. A processing unit may also be referred to as a processor, a processing board, a processing module, a processing device, or the like. Alternatively, a device for implementing a receiving function in the transceiving unit 1410 may be regarded as a receiving unit, and a device for implementing a transmitting function in the transceiving unit 1410 may be regarded as a transmitting unit, that is, the transceiving unit 1410 includes a receiving unit and a transmitting unit. A transceiver unit may also sometimes be referred to as a transceiver, transceiving circuitry, or the like. A receiving unit may also be referred to as a receiver, a receiving circuit, or the like. A transmitting unit may also sometimes be referred to as a transmitter, or a transmitting circuit, etc.

It should be understood that the transceiving unit 1410 is configured to perform the transmitting operation and the receiving operation on the terminal device side in the above method embodiments, and the processing unit 1420 is configured to perform other operations on the terminal device in the above method embodiments besides the transceiving operation.

For example, in one implementation manner, the processing unit 1420 is further configured to execute the processing steps on the terminal device side in the embodiment of the present application. The transceiving unit 1410 is configured to perform transceiving operations in step 401 and/or step 402 in fig. 4, and/or the transceiving unit 1410 is further configured to perform other transceiving steps on the terminal device side in this embodiment of the present application.

When the device for relaying communication is a chip, the chip includes a transceiver unit and a processing unit. The transceiver unit can be an input/output circuit and a communication interface; the processing unit is a processor or a microprocessor or an integrated circuit integrated on the chip.

Optionally, when the apparatus is a terminal device, reference may also be made to the device shown in fig. 15. As an example, the device may perform functions similar to processor 1410 of FIG. 14. In fig. 15, the apparatus includes a processor 1501, a transmit data processor 1503, and a receive data processor 1505. The processing module 830 in the above embodiment may be the processor 1501 in fig. 15, and performs the corresponding functions. The receiving module 810 and the transmitting module 820 in the above embodiments may be the transmitting data processor 1503 and the receiving data processor 1505 in fig. 15. Although fig. 15 shows a channel encoder and a channel decoder, it is understood that these blocks are not limitative and only illustrative to the present embodiment.

Fig. 16 shows another form of the present embodiment. The processing device 1600 includes modules such as a modulation subsystem, a central processing subsystem, and peripheral subsystems. The communication device in this embodiment may act as a modulation subsystem therein. In particular, the modulation subsystem may include a processor 1603 and an interface 1604. The processor 1603 performs the functions of the processing module 810, and the interface 1604 performs the functions of the transceiver module 820. As another variation, the modulation subsystem includes memory 1608, a processor 1603, and a program stored on the memory and executable on the processor that executes the methods of the embodiments shown in fig. 4, 6, and 7. It is noted that the memory 1608 may be non-volatile or volatile, and may be located within the modulation subsystem or within the processing device 1600, as long as the memory 1608 is coupled to the processor 1603.

As another form of the present embodiment, there is provided a computer-readable storage medium having stored thereon instructions that, when executed, perform the method of the above-described method embodiments.

As another form of the present embodiment, there is provided a computer program product containing instructions that, when executed, perform the method of the above-described method embodiments.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented in software, may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions. When loaded and executed on a computer, cause the processes or functions described in accordance with the embodiments of the application to occur, in whole or in part. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer instructions may be stored in a computer readable storage medium or transmitted from one computer readable storage medium to another computer readable storage medium, for example, the computer instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). The computer-readable storage medium can be any available medium that can be accessed by a computer or a data storage device, such as a server, a data center, etc., that incorporates one or more of the available media. The usable medium may be a magnetic medium (e.g., a floppy disk, a hard disk, a magnetic tape), an optical medium (e.g., a Digital Video Disk (DVD)), or a semiconductor medium (e.g., a Solid State Disk (SSD)), among others.

It should be understood that the processor may be an integrated circuit chip, with signal processing capability. In implementation, the steps of the above method embodiments may be performed by integrated logic circuits of hardware in a processor or by instructions in the form of software. The processor may be a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), an off-the-shelf programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic device, or discrete hardware components. The various methods, steps, and logic blocks disclosed in the embodiments of the present application may be implemented or performed. A general purpose processor may be a microprocessor or the processor may be any conventional processor or the like. The steps of the method disclosed in connection with the embodiments of the present application may be directly implemented by a hardware decoding processor, or implemented by a combination of hardware and software modules in the decoding processor. The software module may be located in ram, flash memory, rom, prom, or eprom, registers, etc. storage media as is well known in the art. The storage medium is located in a memory, and a processor reads information in the memory and completes the steps of the method in combination with hardware of the processor.

It will be appreciated that the memory in the embodiments of the subject application can be either volatile memory or nonvolatile memory, or can include both volatile and nonvolatile memory. The non-volatile memory may be a read-only memory (ROM), a Programmable ROM (PROM), an Erasable PROM (EPROM), an Electrically Erasable PROM (EEPROM), or a flash memory. Volatile memory can be Random Access Memory (RAM), which acts as external cache memory. By way of example, but not limitation, many forms of RAM are available, such as Static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), synchronous Dynamic Random Access Memory (SDRAM), double data rate SDRAM, enhanced SDRAM, SLDRAM, synchronous Link DRAM (SLDRAM), and direct bus RAM (DR RAM).

In the present application, "at least one" means one or more, "a plurality" means two or more. "and/or" describes the association relationship of the associated objects, meaning that there may be three relationships, e.g., a and/or B, which may mean: a alone, A and B together, and B alone, wherein A and B may be singular or plural. The character "/" generally indicates that the former and latter associated objects are in an "or" relationship. "at least one of the following" or similar expressions refer to any combination of these items, including any combination of the singular or plural items. For example, at least one (one) of a, b, or c, may represent: a, b, c, a-b, a-c, b-c, or a-b-c, wherein a, b, c may be single or multiple.

It should be appreciated that reference throughout this specification to "one embodiment" or "an embodiment" means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, the appearances of the phrases "in one embodiment" or "in an embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments. It should be understood that, in various embodiments of the present invention, the sequence numbers of the above-mentioned processes do not mean the execution sequence, and the execution sequence of each process should be determined by its function and inherent logic, and should not constitute any limitation on the implementation process of the embodiments of the present invention.

As used in this specification, the terms "component," "module," "system," and the like are intended to refer to a computer-related entity, either hardware, firmware, a combination of hardware and software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, an object, an executable, a thread of execution, a program, and/or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and/or thread of execution and a component can be localized on one computer and/or distributed between 2 or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components may communicate by way of local and/or remote processes such as in accordance with a signal having one or more data packets (e.g., data from two components interacting with another component in a local system, distributed system, and/or across a network such as the internet with other systems by way of the signal).

It should also be understood that the reference herein to first, second, and various numerical designations is merely a convenient division to describe and is not intended to limit the scope of the embodiments of the present application.

It should be understood that the term "and/or" herein is merely one type of association relationship that describes an associated object, meaning that three relationships may exist, e.g., a and/or B may mean: a exists alone, A and B exist simultaneously, and B exists alone. Wherein A or B is present alone, and the number of A or B is not limited. Taking the case of a being present alone, it is understood to have one or more a.

Those of ordinary skill in the art will appreciate that the various illustrative elements and algorithm steps described in connection with the embodiments disclosed herein may be implemented as electronic hardware, or combinations of computer software and electronic hardware. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the implementation. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present application.

It is clear to those skilled in the art that, for convenience and brevity of description, the specific working processes of the above-described systems, apparatuses and units may refer to the corresponding processes in the foregoing method embodiments, and are not described herein again.

In the several embodiments provided in the present application, it should be understood that the disclosed system, apparatus and method may be implemented in other ways. For example, the above-described apparatus embodiments are merely illustrative, and for example, the division of the units is only one logical division, and other divisions may be realized in practice, for example, a plurality of units or components may be combined or integrated into another system, or some features may be omitted, or not executed. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or units, and may be in an electrical, mechanical or other form.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one place, or may be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present application may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit.

Claims

1. A method of relaying communications, comprising:

the method comprises the steps that a first terminal device receives indication information from a second terminal device, and the indication information indicates that the relay service between the first terminal device and a wireless access network device is stopped to be provided;

the first terminal equipment sends a predetermined identifier of a third terminal equipment to the second terminal equipment;

the first terminal device sends first notification information to the radio access network device through the third terminal device, wherein the first notification information indicates that the first terminal device is connected to the radio access network device through a relay service of the third terminal device, and the first notification information also indicates an identifier of the first terminal device;

the first terminal device further sends a second notification message to the radio access network device through a fourth terminal device, where the second notification message is used to indicate that the fourth terminal device can provide a relay service for the first terminal device and the radio access network device simultaneously with the second terminal device or the third terminal device.

2. The method of claim 1, wherein the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than or equal to a preset quality threshold.

3. The method of claim 1, wherein the indication information indicates that a radio link failure has occurred between the second terminal device and the radio access network device.

4. A method of relaying communications, comprising:

the second terminal equipment generates indication information, and the indication information indicates that the relay service between the first terminal equipment and the wireless access network equipment is stopped to be provided;

the second terminal equipment sends the indication information to the first terminal equipment;

the second terminal device receives an identifier of a third terminal device from the first terminal device, wherein the third terminal device is a potential device for providing relay service for the first terminal device and the wireless access network device, and the second terminal device is a device for currently providing relay service for the first terminal device and the wireless access network device;

the second terminal equipment receives data from the first terminal equipment or the wireless access network equipment through a first channel;

the second terminal equipment determines a second channel identifier according to the first channel identifier of the first channel and the first mapping relation;

and the second terminal equipment sends the data received through the first channel to the third terminal equipment through a channel corresponding to the second channel identifier, and the first mapping relation is one-to-one mapping relation of at least one first channel identifier and at least one second channel identifier.

5. The method of claim 4, wherein the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than a preset threshold.

6. The method of claim 4, wherein the indication information indicates that a radio link failure has occurred between the second terminal device and the radio access network device.

7. The method according to any of claims 4 to 6, wherein the second terminal device sending data to be sent of the first terminal device to a third terminal device comprises:

the second terminal device sends a first message, where the first message includes the data to be sent, and the first message also includes an identifier carrying the first terminal device, an identifier of a first channel, and uplink indication information or downlink transmission direction indication information when sending the data to be sent to a third terminal device, and the first channel is used for communication between the first terminal device and the radio access network device.

8. A method for relaying communication, the method being applied to a communication system including a first terminal device, a second terminal device, a third terminal device and a radio access network device, wherein the third terminal device is a device currently providing a relay service for the first terminal device and the radio access network device, and the second terminal device is a device providing a relay service for the first terminal device and the radio access network device before the third terminal device, the method comprising:

the second terminal equipment receives data belonging to the first terminal equipment;

the second terminal device sends a first message to the third terminal device, where the first message includes data of the first terminal device and notification information, the notification information is used to indicate an identifier of the first terminal device, a DRB identifier for data radio bearer, and direction indication information, the DRB identifier is used to indicate a DRB that carries the data between the first terminal device and the radio access network device, and the direction indication information is used to indicate a transmission direction of the data.

9. The method of claim 8, wherein the notification information is carried in sidelink control information SCI, and wherein time domain resources occupied by the SCI are the same as or before time domain resources occupied by the data belonging to the first terminal device.

10. The method of claim 8, wherein the notification information is carried in an adaptation layer of the first message.

11. An apparatus for relaying communications, comprising:

a receiving module, configured to receive indication information from a second terminal device, where the indication information indicates that a relay service between a first terminal device and a radio access network device is stopped being provided;

a sending module, configured to send a predetermined identifier of a third terminal device to the second terminal device;

the sending module is further configured to send notification information to the radio access network device through the third terminal device, where the notification information indicates that the first terminal device is connected to the radio access network device through a relay service of the third terminal device, and the notification information also indicates an identifier of the first terminal device;

the sending module is further configured to send a second notification message to the radio access network device through a fourth terminal device, where the second notification message is used to indicate that the fourth terminal device can provide a relay service for the first terminal device and the radio access network device simultaneously with the second terminal device or the third terminal device.

12. The apparatus of claim 11, wherein the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than or equal to a preset quality threshold.

13. The apparatus of claim 11, wherein the indication information indicates that a radio link failure occurred between the second terminal device and the radio access network device.

14. An apparatus for relaying communications, comprising:

the processing module is used for generating indication information which indicates that the relay service between the first terminal equipment and the wireless access network equipment is stopped to be provided;

a sending module, configured to send the indication information to the first terminal device;

a receiving module, configured to receive an identifier of a third terminal device from the first terminal device, where the third terminal device is a potential device that provides a relay service for the first terminal device and the radio access network device, and the second terminal device is a device that currently provides a relay service for the first terminal device and the radio access network device;

the sending module is further configured to receive data from the first terminal device or the radio access network device through a first channel;

the processing module is further configured to determine a second channel identifier according to the first channel identifier of the first channel and the first mapping relationship;

the sending module is further configured to send the data received by the receiving module through the first channel to the third terminal device through a channel corresponding to the second channel identifier, where the first mapping relationship is a one-to-one mapping relationship between at least one first channel identifier and at least one second channel identifier.

15. The apparatus of claim 14, wherein the indication information indicates that the signal quality between the second terminal device and the radio access network device is less than a preset threshold.

16. The apparatus of claim 14, wherein the indication information indicates that a radio link failure occurs between a second terminal device and the radio access network device.

17. The apparatus according to any one of claims 14 to 16, wherein the sending module is specifically configured to:

and sending a first message, wherein the first message comprises data to be sent, and the first message further comprises an identifier of the first terminal device, an identifier of a first channel and transmission direction indication information, and the first channel is used for communication between the first terminal device and the radio access network device.

18. An apparatus for relaying communication, wherein the apparatus is applied to a communication system including a first terminal device, a second terminal device, a third terminal device and a radio access network device, wherein the third terminal device is a device that currently provides a relay service for the first terminal device and the radio access network device, and the second terminal device is a device that provides a relay service for the first terminal device and the radio access network device before the third terminal device, the apparatus comprising:

a receiving module, configured to receive data belonging to the first terminal device;

a sending module, configured to send a first message to the third terminal device, where the first message includes the data belonging to the first terminal device and notification information, the notification information is used to indicate an identifier of the first terminal device, a DRB identifier for data radio bearer, and direction indication information, the DRB identifier is used to identify a DRB that carries the data between the first terminal device and the radio access network device, and the direction indication information is used to indicate a transmission direction of the data.

19. The apparatus of claim 18, wherein the notification information is carried in sidelink control information SCI, and wherein a time domain resource of the SCI is the same as or before a time domain resource of the data belonging to the first terminal device.

20. The apparatus of claim 18, wherein the notification information is carried in an adaptation layer of the first message.